// De-allocate storage for each of the rows for (int i = 0; i < nrows; i++) { free(iarray[i]); }

// Deallocate storage for the array of row pointers free(iarray); // After previous memory has been cleared, you can reallocate with // whatever values of nrows and ncols you want (subject to "heap" // size limits). ++counter; delay(1000);}

Output:Row 0: 0 1 2Row 1: 3 4 5

Row 0: 1 2 3Row 1: 4 5 6

Row 0: 2 3 4Row 1: 5 6 7

Row 0: 3 4 5Row 1: 6 7 8

Row 0: 4 5 6Row 1: 7 8 9...

This is just an illustration of how to do it. In your loop() you would deallocate the storage then assign new values to nrows and ncols and go through the allocation steps again. I might even write a function to allocate storage for nrows and ncols and another function to deallocate them. I'll leave that up to you.

I am very reluctant to use dynamic memory allocation in any embedded system that I expect to run forever. Why do I have misgivings? Lack of garbage collection in the standard library function malloc(). That's why.

It is possible to allocate and deallocate memory (repeatedly) in such a way that there is enough memory in the heap to do the job but it is fragmented so that that not enough contiguous memory is available to finish it.

I mean, if the application is supposed to do something and quit, that's one thing, but if it is supposed to run forever and you don't know ahead of time how much memory you actually need, then, you are really, really (really) asking for trouble. For simple cases, you might convince yourself that such fragmentation will not occur, but...

That's just an opinion (my opinion), and it's worth exactly what you want it to be worth.

I programing a robot to "High school competition".His task is mapped a "room". He use array to save information about room as square site.False - square is clear True - is there a blockThe informatioun about squares will be save in array under indexes

[y] but I must used negative coordinates.I use 4-quadrants this means 4x 2D array...

I have idea use one array with offset zero because if I use array [100][100] and as zero is 50.The "room" can be long 7,5m*2 (one square is 15cm) which is enough But I'd solved it universally and more elegant.

I am very reluctant to use dynamic memory allocation in any embedded system that I expect to run forever. Why do I have misgivings? Lack of garbage collection in the standard library function malloc(). That's why.

It is possible to allocate and deallocate memory (repeatedly) in such a way that there is enough memory in the heap to do the job but it is fragmented so that that not enough contiguous memory is available to finish it.

I mean, if the application is supposed to do something and quit, that's one thing, but if it is supposed to run forever and you don't know ahead of time how much memory you actually need, then, you are really, really (really) asking for trouble. For simple cases, you might convince yourself that such fragmentation will not occur, but...

That's just an opinion (my opinion), and it's worth exactly what you want it to be worth.

not to mention that even if you did everything right it is still really tough to figure out just how much memory you are allocating. And if you do know, why does it need to be dynamic?

Quote

[The robot's] task is mapped a "room". He use array to save information about room as square site.

They make SD card shields for arduino and it sounds like you may need to store a lot of data (>8k). It may be worth it to think of a linear data format that can be parsed later and store it to an SD card since they are cheap, easy, and give virtually unlimited storage.

No I didnt use arduino board. I made own board but I can use bluetooh for send data to PC or any device ... I use this robot in "test arena" c. 4x4square and for test the functionality of the algorithm in larger areas can be used bluetooh.